THIOPURINE METABOLITES

Components
6-Thioguanine (6-TG), 6-Methylmercaptopurine (6-MMP)

Specimen Required
A trough specimen is required (collected within 1 hour prior to the next dose). Draw blood in a lavender EDTA tube. Send 5.0 mL whole blood (2.5 mL minimum) refrigerated.

Rejection Criteria
Hemolysis, frozen samples, heparin whole blood

Methodology
Liquid Chromatography/Tandem Mass Spectometry (LC/MS/MS)

Stability
Room temperature: 24 hours; Refrigerated: 5 days; Frozen: Unacceptable

Reference Range
6-TG:   235-400 pmol/8 x 10 (8) RBC  
6-MMP:   <5700 pmol/8 x 10 (8) RBC  

Performed
Tuesday-Saturday

Turnaround Time4-6 days
Test CodeTPMTM
CPT-4 Code (s)
80299
LOINC Codes
6-Thioguanine:   32660-3  
6-Methylmercaptopurine:   32654-6  

Warde
Medical
Laboratory